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1/*
2 * linux/fs/lockd/mon.c
3 *
4 * The kernel statd client.
5 *
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
8
9#include <linux/types.h>
10#include <linux/utsname.h>
11#include <linux/kernel.h>
12#include <linux/ktime.h>
13#include <linux/slab.h>
14
15#include <linux/sunrpc/clnt.h>
16#include <linux/sunrpc/xprtsock.h>
17#include <linux/sunrpc/svc.h>
18#include <linux/lockd/lockd.h>
19
20#include <asm/unaligned.h>
21
22#define NLMDBG_FACILITY NLMDBG_MONITOR
23#define NSM_PROGRAM 100024
24#define NSM_VERSION 1
25
26enum {
27 NSMPROC_NULL,
28 NSMPROC_STAT,
29 NSMPROC_MON,
30 NSMPROC_UNMON,
31 NSMPROC_UNMON_ALL,
32 NSMPROC_SIMU_CRASH,
33 NSMPROC_NOTIFY,
34};
35
36struct nsm_args {
37 struct nsm_private *priv;
38 u32 prog; /* RPC callback info */
39 u32 vers;
40 u32 proc;
41
42 char *mon_name;
43};
44
45struct nsm_res {
46 u32 status;
47 u32 state;
48};
49
50static struct rpc_program nsm_program;
51static LIST_HEAD(nsm_handles);
52static DEFINE_SPINLOCK(nsm_lock);
53
54/*
55 * Local NSM state
56 */
57u32 __read_mostly nsm_local_state;
58int __read_mostly nsm_use_hostnames;
59
60static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
61{
62 return (struct sockaddr *)&nsm->sm_addr;
63}
64
65static struct rpc_clnt *nsm_create(void)
66{
67 struct sockaddr_in sin = {
68 .sin_family = AF_INET,
69 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
70 };
71 struct rpc_create_args args = {
72 .net = &init_net,
73 .protocol = XPRT_TRANSPORT_UDP,
74 .address = (struct sockaddr *)&sin,
75 .addrsize = sizeof(sin),
76 .servername = "rpc.statd",
77 .program = &nsm_program,
78 .version = NSM_VERSION,
79 .authflavor = RPC_AUTH_NULL,
80 .flags = RPC_CLNT_CREATE_NOPING,
81 };
82
83 return rpc_create(&args);
84}
85
86static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
87{
88 struct rpc_clnt *clnt;
89 int status;
90 struct nsm_args args = {
91 .priv = &nsm->sm_priv,
92 .prog = NLM_PROGRAM,
93 .vers = 3,
94 .proc = NLMPROC_NSM_NOTIFY,
95 .mon_name = nsm->sm_mon_name,
96 };
97 struct rpc_message msg = {
98 .rpc_argp = &args,
99 .rpc_resp = res,
100 };
101
102 clnt = nsm_create();
103 if (IS_ERR(clnt)) {
104 status = PTR_ERR(clnt);
105 dprintk("lockd: failed to create NSM upcall transport, "
106 "status=%d\n", status);
107 goto out;
108 }
109
110 memset(res, 0, sizeof(*res));
111
112 msg.rpc_proc = &clnt->cl_procinfo[proc];
113 status = rpc_call_sync(clnt, &msg, 0);
114 if (status < 0)
115 dprintk("lockd: NSM upcall RPC failed, status=%d\n",
116 status);
117 else
118 status = 0;
119 rpc_shutdown_client(clnt);
120 out:
121 return status;
122}
123
124/**
125 * nsm_monitor - Notify a peer in case we reboot
126 * @host: pointer to nlm_host of peer to notify
127 *
128 * If this peer is not already monitored, this function sends an
129 * upcall to the local rpc.statd to record the name/address of
130 * the peer to notify in case we reboot.
131 *
132 * Returns zero if the peer is monitored by the local rpc.statd;
133 * otherwise a negative errno value is returned.
134 */
135int nsm_monitor(const struct nlm_host *host)
136{
137 struct nsm_handle *nsm = host->h_nsmhandle;
138 struct nsm_res res;
139 int status;
140
141 dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
142
143 if (nsm->sm_monitored)
144 return 0;
145
146 /*
147 * Choose whether to record the caller_name or IP address of
148 * this peer in the local rpc.statd's database.
149 */
150 nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
151
152 status = nsm_mon_unmon(nsm, NSMPROC_MON, &res);
153 if (unlikely(res.status != 0))
154 status = -EIO;
155 if (unlikely(status < 0)) {
156 printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
157 return status;
158 }
159
160 nsm->sm_monitored = 1;
161 if (unlikely(nsm_local_state != res.state)) {
162 nsm_local_state = res.state;
163 dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
164 }
165 return 0;
166}
167
168/**
169 * nsm_unmonitor - Unregister peer notification
170 * @host: pointer to nlm_host of peer to stop monitoring
171 *
172 * If this peer is monitored, this function sends an upcall to
173 * tell the local rpc.statd not to send this peer a notification
174 * when we reboot.
175 */
176void nsm_unmonitor(const struct nlm_host *host)
177{
178 struct nsm_handle *nsm = host->h_nsmhandle;
179 struct nsm_res res;
180 int status;
181
182 if (atomic_read(&nsm->sm_count) == 1
183 && nsm->sm_monitored && !nsm->sm_sticky) {
184 dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
185
186 status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res);
187 if (res.status != 0)
188 status = -EIO;
189 if (status < 0)
190 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
191 nsm->sm_name);
192 else
193 nsm->sm_monitored = 0;
194 }
195}
196
197static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
198 const size_t len)
199{
200 struct nsm_handle *nsm;
201
202 list_for_each_entry(nsm, &nsm_handles, sm_link)
203 if (strlen(nsm->sm_name) == len &&
204 memcmp(nsm->sm_name, hostname, len) == 0)
205 return nsm;
206 return NULL;
207}
208
209static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap)
210{
211 struct nsm_handle *nsm;
212
213 list_for_each_entry(nsm, &nsm_handles, sm_link)
214 if (rpc_cmp_addr(nsm_addr(nsm), sap))
215 return nsm;
216 return NULL;
217}
218
219static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
220{
221 struct nsm_handle *nsm;
222
223 list_for_each_entry(nsm, &nsm_handles, sm_link)
224 if (memcmp(nsm->sm_priv.data, priv->data,
225 sizeof(priv->data)) == 0)
226 return nsm;
227 return NULL;
228}
229
230/*
231 * Construct a unique cookie to match this nsm_handle to this monitored
232 * host. It is passed to the local rpc.statd via NSMPROC_MON, and
233 * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
234 * requests.
235 *
236 * The NSM protocol requires that these cookies be unique while the
237 * system is running. We prefer a stronger requirement of making them
238 * unique across reboots. If user space bugs cause a stale cookie to
239 * be sent to the kernel, it could cause the wrong host to lose its
240 * lock state if cookies were not unique across reboots.
241 *
242 * The cookies are exposed only to local user space via loopback. They
243 * do not appear on the physical network. If we want greater security
244 * for some reason, nsm_init_private() could perform a one-way hash to
245 * obscure the contents of the cookie.
246 */
247static void nsm_init_private(struct nsm_handle *nsm)
248{
249 u64 *p = (u64 *)&nsm->sm_priv.data;
250 struct timespec ts;
251 s64 ns;
252
253 ktime_get_ts(&ts);
254 ns = timespec_to_ns(&ts);
255 put_unaligned(ns, p);
256 put_unaligned((unsigned long)nsm, p + 1);
257}
258
259static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
260 const size_t salen,
261 const char *hostname,
262 const size_t hostname_len)
263{
264 struct nsm_handle *new;
265
266 new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
267 if (unlikely(new == NULL))
268 return NULL;
269
270 atomic_set(&new->sm_count, 1);
271 new->sm_name = (char *)(new + 1);
272 memcpy(nsm_addr(new), sap, salen);
273 new->sm_addrlen = salen;
274 nsm_init_private(new);
275
276 if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
277 sizeof(new->sm_addrbuf)) == 0)
278 (void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
279 "unsupported address family");
280 memcpy(new->sm_name, hostname, hostname_len);
281 new->sm_name[hostname_len] = '\0';
282
283 return new;
284}
285
286/**
287 * nsm_get_handle - Find or create a cached nsm_handle
288 * @sap: pointer to socket address of handle to find
289 * @salen: length of socket address
290 * @hostname: pointer to C string containing hostname to find
291 * @hostname_len: length of C string
292 *
293 * Behavior is modulated by the global nsm_use_hostnames variable.
294 *
295 * Returns a cached nsm_handle after bumping its ref count, or
296 * returns a fresh nsm_handle if a handle that matches @sap and/or
297 * @hostname cannot be found in the handle cache. Returns NULL if
298 * an error occurs.
299 */
300struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
301 const size_t salen, const char *hostname,
302 const size_t hostname_len)
303{
304 struct nsm_handle *cached, *new = NULL;
305
306 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
307 if (printk_ratelimit()) {
308 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
309 "in NFS lock request\n",
310 (int)hostname_len, hostname);
311 }
312 return NULL;
313 }
314
315retry:
316 spin_lock(&nsm_lock);
317
318 if (nsm_use_hostnames && hostname != NULL)
319 cached = nsm_lookup_hostname(hostname, hostname_len);
320 else
321 cached = nsm_lookup_addr(sap);
322
323 if (cached != NULL) {
324 atomic_inc(&cached->sm_count);
325 spin_unlock(&nsm_lock);
326 kfree(new);
327 dprintk("lockd: found nsm_handle for %s (%s), "
328 "cnt %d\n", cached->sm_name,
329 cached->sm_addrbuf,
330 atomic_read(&cached->sm_count));
331 return cached;
332 }
333
334 if (new != NULL) {
335 list_add(&new->sm_link, &nsm_handles);
336 spin_unlock(&nsm_lock);
337 dprintk("lockd: created nsm_handle for %s (%s)\n",
338 new->sm_name, new->sm_addrbuf);
339 return new;
340 }
341
342 spin_unlock(&nsm_lock);
343
344 new = nsm_create_handle(sap, salen, hostname, hostname_len);
345 if (unlikely(new == NULL))
346 return NULL;
347 goto retry;
348}
349
350/**
351 * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
352 * @info: pointer to NLMPROC_SM_NOTIFY arguments
353 *
354 * Returns a matching nsm_handle if found in the nsm cache. The returned
355 * nsm_handle's reference count is bumped. Otherwise returns NULL if some
356 * error occurred.
357 */
358struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
359{
360 struct nsm_handle *cached;
361
362 spin_lock(&nsm_lock);
363
364 cached = nsm_lookup_priv(&info->priv);
365 if (unlikely(cached == NULL)) {
366 spin_unlock(&nsm_lock);
367 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
368 info->len, info->mon);
369 return cached;
370 }
371
372 atomic_inc(&cached->sm_count);
373 spin_unlock(&nsm_lock);
374
375 dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
376 cached->sm_name, cached->sm_addrbuf,
377 atomic_read(&cached->sm_count));
378 return cached;
379}
380
381/**
382 * nsm_release - Release an NSM handle
383 * @nsm: pointer to handle to be released
384 *
385 */
386void nsm_release(struct nsm_handle *nsm)
387{
388 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
389 list_del(&nsm->sm_link);
390 spin_unlock(&nsm_lock);
391 dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
392 nsm->sm_name, nsm->sm_addrbuf);
393 kfree(nsm);
394 }
395}
396
397/*
398 * XDR functions for NSM.
399 *
400 * See http://www.opengroup.org/ for details on the Network
401 * Status Monitor wire protocol.
402 */
403
404static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
405{
406 const u32 len = strlen(string);
407 __be32 *p;
408
409 BUG_ON(len > SM_MAXSTRLEN);
410 p = xdr_reserve_space(xdr, 4 + len);
411 xdr_encode_opaque(p, string, len);
412}
413
414/*
415 * "mon_name" specifies the host to be monitored.
416 */
417static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
418{
419 encode_nsm_string(xdr, argp->mon_name);
420}
421
422/*
423 * The "my_id" argument specifies the hostname and RPC procedure
424 * to be called when the status manager receives notification
425 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
426 * has changed.
427 */
428static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
429{
430 __be32 *p;
431
432 encode_nsm_string(xdr, utsname()->nodename);
433 p = xdr_reserve_space(xdr, 4 + 4 + 4);
434 *p++ = cpu_to_be32(argp->prog);
435 *p++ = cpu_to_be32(argp->vers);
436 *p = cpu_to_be32(argp->proc);
437}
438
439/*
440 * The "mon_id" argument specifies the non-private arguments
441 * of an NSMPROC_MON or NSMPROC_UNMON call.
442 */
443static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
444{
445 encode_mon_name(xdr, argp);
446 encode_my_id(xdr, argp);
447}
448
449/*
450 * The "priv" argument may contain private information required
451 * by the NSMPROC_MON call. This information will be supplied in the
452 * NLMPROC_SM_NOTIFY call.
453 */
454static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
455{
456 __be32 *p;
457
458 p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
459 xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
460}
461
462static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr,
463 const struct nsm_args *argp)
464{
465 encode_mon_id(xdr, argp);
466 encode_priv(xdr, argp);
467}
468
469static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr,
470 const struct nsm_args *argp)
471{
472 encode_mon_id(xdr, argp);
473}
474
475static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp,
476 struct xdr_stream *xdr,
477 struct nsm_res *resp)
478{
479 __be32 *p;
480
481 p = xdr_inline_decode(xdr, 4 + 4);
482 if (unlikely(p == NULL))
483 return -EIO;
484 resp->status = be32_to_cpup(p++);
485 resp->state = be32_to_cpup(p);
486
487 dprintk("lockd: %s status %d state %d\n",
488 __func__, resp->status, resp->state);
489 return 0;
490}
491
492static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
493 struct xdr_stream *xdr,
494 struct nsm_res *resp)
495{
496 __be32 *p;
497
498 p = xdr_inline_decode(xdr, 4);
499 if (unlikely(p == NULL))
500 return -EIO;
501 resp->state = be32_to_cpup(p);
502
503 dprintk("lockd: %s state %d\n", __func__, resp->state);
504 return 0;
505}
506
507#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
508#define SM_my_id_sz (SM_my_name_sz+3)
509#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
510#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
511#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
512#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
513#define SM_monres_sz 2
514#define SM_unmonres_sz 1
515
516static struct rpc_procinfo nsm_procedures[] = {
517[NSMPROC_MON] = {
518 .p_proc = NSMPROC_MON,
519 .p_encode = (kxdreproc_t)nsm_xdr_enc_mon,
520 .p_decode = (kxdrdproc_t)nsm_xdr_dec_stat_res,
521 .p_arglen = SM_mon_sz,
522 .p_replen = SM_monres_sz,
523 .p_statidx = NSMPROC_MON,
524 .p_name = "MONITOR",
525 },
526[NSMPROC_UNMON] = {
527 .p_proc = NSMPROC_UNMON,
528 .p_encode = (kxdreproc_t)nsm_xdr_enc_unmon,
529 .p_decode = (kxdrdproc_t)nsm_xdr_dec_stat,
530 .p_arglen = SM_mon_id_sz,
531 .p_replen = SM_unmonres_sz,
532 .p_statidx = NSMPROC_UNMON,
533 .p_name = "UNMONITOR",
534 },
535};
536
537static struct rpc_version nsm_version1 = {
538 .number = 1,
539 .nrprocs = ARRAY_SIZE(nsm_procedures),
540 .procs = nsm_procedures
541};
542
543static struct rpc_version * nsm_version[] = {
544 [1] = &nsm_version1,
545};
546
547static struct rpc_stat nsm_stats;
548
549static struct rpc_program nsm_program = {
550 .name = "statd",
551 .number = NSM_PROGRAM,
552 .nrvers = ARRAY_SIZE(nsm_version),
553 .version = nsm_version,
554 .stats = &nsm_stats
555};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/lockd/mon.c
4 *
5 * The kernel statd client.
6 *
7 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
8 */
9
10#include <linux/types.h>
11#include <linux/kernel.h>
12#include <linux/ktime.h>
13#include <linux/slab.h>
14
15#include <linux/sunrpc/clnt.h>
16#include <linux/sunrpc/addr.h>
17#include <linux/sunrpc/xprtsock.h>
18#include <linux/sunrpc/svc.h>
19#include <linux/lockd/lockd.h>
20
21#include <asm/unaligned.h>
22
23#include "netns.h"
24
25#define NLMDBG_FACILITY NLMDBG_MONITOR
26#define NSM_PROGRAM 100024
27#define NSM_VERSION 1
28
29enum {
30 NSMPROC_NULL,
31 NSMPROC_STAT,
32 NSMPROC_MON,
33 NSMPROC_UNMON,
34 NSMPROC_UNMON_ALL,
35 NSMPROC_SIMU_CRASH,
36 NSMPROC_NOTIFY,
37};
38
39struct nsm_args {
40 struct nsm_private *priv;
41 u32 prog; /* RPC callback info */
42 u32 vers;
43 u32 proc;
44
45 char *mon_name;
46 const char *nodename;
47};
48
49struct nsm_res {
50 u32 status;
51 u32 state;
52};
53
54static const struct rpc_program nsm_program;
55static DEFINE_SPINLOCK(nsm_lock);
56
57/*
58 * Local NSM state
59 */
60u32 __read_mostly nsm_local_state;
61bool __read_mostly nsm_use_hostnames;
62
63static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
64{
65 return (struct sockaddr *)&nsm->sm_addr;
66}
67
68static struct rpc_clnt *nsm_create(struct net *net, const char *nodename)
69{
70 struct sockaddr_in sin = {
71 .sin_family = AF_INET,
72 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
73 };
74 struct rpc_create_args args = {
75 .net = net,
76 .protocol = XPRT_TRANSPORT_TCP,
77 .address = (struct sockaddr *)&sin,
78 .addrsize = sizeof(sin),
79 .servername = "rpc.statd",
80 .nodename = nodename,
81 .program = &nsm_program,
82 .version = NSM_VERSION,
83 .authflavor = RPC_AUTH_NULL,
84 .flags = RPC_CLNT_CREATE_NOPING,
85 .cred = current_cred(),
86 };
87
88 return rpc_create(&args);
89}
90
91static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,
92 const struct nlm_host *host)
93{
94 int status;
95 struct rpc_clnt *clnt;
96 struct nsm_args args = {
97 .priv = &nsm->sm_priv,
98 .prog = NLM_PROGRAM,
99 .vers = 3,
100 .proc = NLMPROC_NSM_NOTIFY,
101 .mon_name = nsm->sm_mon_name,
102 .nodename = host->nodename,
103 };
104 struct rpc_message msg = {
105 .rpc_argp = &args,
106 .rpc_resp = res,
107 };
108
109 memset(res, 0, sizeof(*res));
110
111 clnt = nsm_create(host->net, host->nodename);
112 if (IS_ERR(clnt)) {
113 dprintk("lockd: failed to create NSM upcall transport, "
114 "status=%ld, net=%x\n", PTR_ERR(clnt),
115 host->net->ns.inum);
116 return PTR_ERR(clnt);
117 }
118
119 msg.rpc_proc = &clnt->cl_procinfo[proc];
120 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
121 if (status == -ECONNREFUSED) {
122 dprintk("lockd: NSM upcall RPC failed, status=%d, forcing rebind\n",
123 status);
124 rpc_force_rebind(clnt);
125 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
126 }
127 if (status < 0)
128 dprintk("lockd: NSM upcall RPC failed, status=%d\n",
129 status);
130 else
131 status = 0;
132
133 rpc_shutdown_client(clnt);
134 return status;
135}
136
137/**
138 * nsm_monitor - Notify a peer in case we reboot
139 * @host: pointer to nlm_host of peer to notify
140 *
141 * If this peer is not already monitored, this function sends an
142 * upcall to the local rpc.statd to record the name/address of
143 * the peer to notify in case we reboot.
144 *
145 * Returns zero if the peer is monitored by the local rpc.statd;
146 * otherwise a negative errno value is returned.
147 */
148int nsm_monitor(const struct nlm_host *host)
149{
150 struct nsm_handle *nsm = host->h_nsmhandle;
151 struct nsm_res res;
152 int status;
153
154 dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
155
156 if (nsm->sm_monitored)
157 return 0;
158
159 /*
160 * Choose whether to record the caller_name or IP address of
161 * this peer in the local rpc.statd's database.
162 */
163 nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
164
165 status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, host);
166 if (unlikely(res.status != 0))
167 status = -EIO;
168 if (unlikely(status < 0)) {
169 pr_notice_ratelimited("lockd: cannot monitor %s\n", nsm->sm_name);
170 return status;
171 }
172
173 nsm->sm_monitored = 1;
174 if (unlikely(nsm_local_state != res.state)) {
175 nsm_local_state = res.state;
176 dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
177 }
178 return 0;
179}
180
181/**
182 * nsm_unmonitor - Unregister peer notification
183 * @host: pointer to nlm_host of peer to stop monitoring
184 *
185 * If this peer is monitored, this function sends an upcall to
186 * tell the local rpc.statd not to send this peer a notification
187 * when we reboot.
188 */
189void nsm_unmonitor(const struct nlm_host *host)
190{
191 struct nsm_handle *nsm = host->h_nsmhandle;
192 struct nsm_res res;
193 int status;
194
195 if (refcount_read(&nsm->sm_count) == 1
196 && nsm->sm_monitored && !nsm->sm_sticky) {
197 dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
198
199 status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, host);
200 if (res.status != 0)
201 status = -EIO;
202 if (status < 0)
203 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
204 nsm->sm_name);
205 else
206 nsm->sm_monitored = 0;
207 }
208}
209
210static struct nsm_handle *nsm_lookup_hostname(const struct list_head *nsm_handles,
211 const char *hostname, const size_t len)
212{
213 struct nsm_handle *nsm;
214
215 list_for_each_entry(nsm, nsm_handles, sm_link)
216 if (strlen(nsm->sm_name) == len &&
217 memcmp(nsm->sm_name, hostname, len) == 0)
218 return nsm;
219 return NULL;
220}
221
222static struct nsm_handle *nsm_lookup_addr(const struct list_head *nsm_handles,
223 const struct sockaddr *sap)
224{
225 struct nsm_handle *nsm;
226
227 list_for_each_entry(nsm, nsm_handles, sm_link)
228 if (rpc_cmp_addr(nsm_addr(nsm), sap))
229 return nsm;
230 return NULL;
231}
232
233static struct nsm_handle *nsm_lookup_priv(const struct list_head *nsm_handles,
234 const struct nsm_private *priv)
235{
236 struct nsm_handle *nsm;
237
238 list_for_each_entry(nsm, nsm_handles, sm_link)
239 if (memcmp(nsm->sm_priv.data, priv->data,
240 sizeof(priv->data)) == 0)
241 return nsm;
242 return NULL;
243}
244
245/*
246 * Construct a unique cookie to match this nsm_handle to this monitored
247 * host. It is passed to the local rpc.statd via NSMPROC_MON, and
248 * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
249 * requests.
250 *
251 * The NSM protocol requires that these cookies be unique while the
252 * system is running. We prefer a stronger requirement of making them
253 * unique across reboots. If user space bugs cause a stale cookie to
254 * be sent to the kernel, it could cause the wrong host to lose its
255 * lock state if cookies were not unique across reboots.
256 *
257 * The cookies are exposed only to local user space via loopback. They
258 * do not appear on the physical network. If we want greater security
259 * for some reason, nsm_init_private() could perform a one-way hash to
260 * obscure the contents of the cookie.
261 */
262static void nsm_init_private(struct nsm_handle *nsm)
263{
264 u64 *p = (u64 *)&nsm->sm_priv.data;
265 s64 ns;
266
267 ns = ktime_get_ns();
268 put_unaligned(ns, p);
269 put_unaligned((unsigned long)nsm, p + 1);
270}
271
272static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
273 const size_t salen,
274 const char *hostname,
275 const size_t hostname_len)
276{
277 struct nsm_handle *new;
278
279 if (!hostname)
280 return NULL;
281
282 new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
283 if (unlikely(new == NULL))
284 return NULL;
285
286 refcount_set(&new->sm_count, 1);
287 new->sm_name = (char *)(new + 1);
288 memcpy(nsm_addr(new), sap, salen);
289 new->sm_addrlen = salen;
290 nsm_init_private(new);
291
292 if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
293 sizeof(new->sm_addrbuf)) == 0)
294 (void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
295 "unsupported address family");
296 memcpy(new->sm_name, hostname, hostname_len);
297 new->sm_name[hostname_len] = '\0';
298
299 return new;
300}
301
302/**
303 * nsm_get_handle - Find or create a cached nsm_handle
304 * @net: network namespace
305 * @sap: pointer to socket address of handle to find
306 * @salen: length of socket address
307 * @hostname: pointer to C string containing hostname to find
308 * @hostname_len: length of C string
309 *
310 * Behavior is modulated by the global nsm_use_hostnames variable.
311 *
312 * Returns a cached nsm_handle after bumping its ref count, or
313 * returns a fresh nsm_handle if a handle that matches @sap and/or
314 * @hostname cannot be found in the handle cache. Returns NULL if
315 * an error occurs.
316 */
317struct nsm_handle *nsm_get_handle(const struct net *net,
318 const struct sockaddr *sap,
319 const size_t salen, const char *hostname,
320 const size_t hostname_len)
321{
322 struct nsm_handle *cached, *new = NULL;
323 struct lockd_net *ln = net_generic(net, lockd_net_id);
324
325 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
326 if (printk_ratelimit()) {
327 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
328 "in NFS lock request\n",
329 (int)hostname_len, hostname);
330 }
331 return NULL;
332 }
333
334retry:
335 spin_lock(&nsm_lock);
336
337 if (nsm_use_hostnames && hostname != NULL)
338 cached = nsm_lookup_hostname(&ln->nsm_handles,
339 hostname, hostname_len);
340 else
341 cached = nsm_lookup_addr(&ln->nsm_handles, sap);
342
343 if (cached != NULL) {
344 refcount_inc(&cached->sm_count);
345 spin_unlock(&nsm_lock);
346 kfree(new);
347 dprintk("lockd: found nsm_handle for %s (%s), "
348 "cnt %d\n", cached->sm_name,
349 cached->sm_addrbuf,
350 refcount_read(&cached->sm_count));
351 return cached;
352 }
353
354 if (new != NULL) {
355 list_add(&new->sm_link, &ln->nsm_handles);
356 spin_unlock(&nsm_lock);
357 dprintk("lockd: created nsm_handle for %s (%s)\n",
358 new->sm_name, new->sm_addrbuf);
359 return new;
360 }
361
362 spin_unlock(&nsm_lock);
363
364 new = nsm_create_handle(sap, salen, hostname, hostname_len);
365 if (unlikely(new == NULL))
366 return NULL;
367 goto retry;
368}
369
370/**
371 * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
372 * @net: network namespace
373 * @info: pointer to NLMPROC_SM_NOTIFY arguments
374 *
375 * Returns a matching nsm_handle if found in the nsm cache. The returned
376 * nsm_handle's reference count is bumped. Otherwise returns NULL if some
377 * error occurred.
378 */
379struct nsm_handle *nsm_reboot_lookup(const struct net *net,
380 const struct nlm_reboot *info)
381{
382 struct nsm_handle *cached;
383 struct lockd_net *ln = net_generic(net, lockd_net_id);
384
385 spin_lock(&nsm_lock);
386
387 cached = nsm_lookup_priv(&ln->nsm_handles, &info->priv);
388 if (unlikely(cached == NULL)) {
389 spin_unlock(&nsm_lock);
390 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
391 info->len, info->mon);
392 return cached;
393 }
394
395 refcount_inc(&cached->sm_count);
396 spin_unlock(&nsm_lock);
397
398 dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
399 cached->sm_name, cached->sm_addrbuf,
400 refcount_read(&cached->sm_count));
401 return cached;
402}
403
404/**
405 * nsm_release - Release an NSM handle
406 * @nsm: pointer to handle to be released
407 *
408 */
409void nsm_release(struct nsm_handle *nsm)
410{
411 if (refcount_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
412 list_del(&nsm->sm_link);
413 spin_unlock(&nsm_lock);
414 dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
415 nsm->sm_name, nsm->sm_addrbuf);
416 kfree(nsm);
417 }
418}
419
420/*
421 * XDR functions for NSM.
422 *
423 * See https://www.opengroup.org/ for details on the Network
424 * Status Monitor wire protocol.
425 */
426
427static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
428{
429 const u32 len = strlen(string);
430 __be32 *p;
431
432 p = xdr_reserve_space(xdr, 4 + len);
433 xdr_encode_opaque(p, string, len);
434}
435
436/*
437 * "mon_name" specifies the host to be monitored.
438 */
439static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
440{
441 encode_nsm_string(xdr, argp->mon_name);
442}
443
444/*
445 * The "my_id" argument specifies the hostname and RPC procedure
446 * to be called when the status manager receives notification
447 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
448 * has changed.
449 */
450static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
451{
452 __be32 *p;
453
454 encode_nsm_string(xdr, argp->nodename);
455 p = xdr_reserve_space(xdr, 4 + 4 + 4);
456 *p++ = cpu_to_be32(argp->prog);
457 *p++ = cpu_to_be32(argp->vers);
458 *p = cpu_to_be32(argp->proc);
459}
460
461/*
462 * The "mon_id" argument specifies the non-private arguments
463 * of an NSMPROC_MON or NSMPROC_UNMON call.
464 */
465static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
466{
467 encode_mon_name(xdr, argp);
468 encode_my_id(xdr, argp);
469}
470
471/*
472 * The "priv" argument may contain private information required
473 * by the NSMPROC_MON call. This information will be supplied in the
474 * NLMPROC_SM_NOTIFY call.
475 */
476static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
477{
478 __be32 *p;
479
480 p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
481 xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
482}
483
484static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr,
485 const void *argp)
486{
487 encode_mon_id(xdr, argp);
488 encode_priv(xdr, argp);
489}
490
491static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr,
492 const void *argp)
493{
494 encode_mon_id(xdr, argp);
495}
496
497static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp,
498 struct xdr_stream *xdr,
499 void *data)
500{
501 struct nsm_res *resp = data;
502 __be32 *p;
503
504 p = xdr_inline_decode(xdr, 4 + 4);
505 if (unlikely(p == NULL))
506 return -EIO;
507 resp->status = be32_to_cpup(p++);
508 resp->state = be32_to_cpup(p);
509
510 dprintk("lockd: %s status %d state %d\n",
511 __func__, resp->status, resp->state);
512 return 0;
513}
514
515static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
516 struct xdr_stream *xdr,
517 void *data)
518{
519 struct nsm_res *resp = data;
520 __be32 *p;
521
522 p = xdr_inline_decode(xdr, 4);
523 if (unlikely(p == NULL))
524 return -EIO;
525 resp->state = be32_to_cpup(p);
526
527 dprintk("lockd: %s state %d\n", __func__, resp->state);
528 return 0;
529}
530
531#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
532#define SM_my_id_sz (SM_my_name_sz+3)
533#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
534#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
535#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
536#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
537#define SM_monres_sz 2
538#define SM_unmonres_sz 1
539
540static const struct rpc_procinfo nsm_procedures[] = {
541[NSMPROC_MON] = {
542 .p_proc = NSMPROC_MON,
543 .p_encode = nsm_xdr_enc_mon,
544 .p_decode = nsm_xdr_dec_stat_res,
545 .p_arglen = SM_mon_sz,
546 .p_replen = SM_monres_sz,
547 .p_statidx = NSMPROC_MON,
548 .p_name = "MONITOR",
549 },
550[NSMPROC_UNMON] = {
551 .p_proc = NSMPROC_UNMON,
552 .p_encode = nsm_xdr_enc_unmon,
553 .p_decode = nsm_xdr_dec_stat,
554 .p_arglen = SM_mon_id_sz,
555 .p_replen = SM_unmonres_sz,
556 .p_statidx = NSMPROC_UNMON,
557 .p_name = "UNMONITOR",
558 },
559};
560
561static unsigned int nsm_version1_counts[ARRAY_SIZE(nsm_procedures)];
562static const struct rpc_version nsm_version1 = {
563 .number = 1,
564 .nrprocs = ARRAY_SIZE(nsm_procedures),
565 .procs = nsm_procedures,
566 .counts = nsm_version1_counts,
567};
568
569static const struct rpc_version *nsm_version[] = {
570 [1] = &nsm_version1,
571};
572
573static struct rpc_stat nsm_stats;
574
575static const struct rpc_program nsm_program = {
576 .name = "statd",
577 .number = NSM_PROGRAM,
578 .nrvers = ARRAY_SIZE(nsm_version),
579 .version = nsm_version,
580 .stats = &nsm_stats
581};